The incorrect statement for orthoboric acid is

1.  It can not be titrated satisfactorily with NaOH, as a sharp endpoint is not obtain

2.  The acidity of its aqueous solution increases upon the addition of ethylene glycol

3.  It is a weak electrolyte in water

4.  It has a three-dimensional structure due to hydrogen bonding

The coordination number of Al in aluminates is:

1.  3

2.  6

3.  1

4.  4

Which of the following oxide is mixed oxide?

1.  ${\mathrm{PbO}}_2$

2.  ${\mathrm{SnO}}_2$

3.  ${\mathrm{Pb}}_2{O}_3$

4.  ${\mathrm{Pb}}_3{O}_4$

Select the correct statement(s) regarding the following reaction sequence

1.  The compound (A) is ${\left({\mathrm{CH}}_3\right)}_2{\mathrm{SiCl}}_2$

2.  The compound D is SiC

3.  The compound (B) is ${\left({\mathrm{CH}}_3\right)}_2\mathrm{Si}{\left(\mathrm{OH}\right)}_2$

4.  All of these 

The number of double bonds at alternate position in ${\mathrm{C}}_{60}$ molecule are

1.  20

2.  25

3.  30

4.  36

Incorrect statement among the following is

1.  ${\mathrm{B}}_{\mathrm{n}}{\mathrm{H}}_{\mathrm{n}+6}$ are known as arachnoboranes

2.  Indium hydride is a polymeric solid

3.  ${\mathrm{AlH}}_3$ is a monomeric planar molecule

4.  Nido-boranes have the general formula ${\mathrm{B}}_{\mathrm{n}}{\mathrm{H}}_{\mathrm{n}+4}$

Which of the following species decomposes easily?

1.  ${\mathrm{Pbl}}_2$

2.  ${\mathrm{Pbl}}_4$

3.  $\mathrm{Pb}{\left({\mathrm{CH}}_3\mathrm{COO}\right)}_4$

4.  ${\mathrm{PbCl}}_2$

Which of the strong oxidizing agent among the following?

1.  ${\mathrm{Tl}}^{3+}$

2.  ${\mathrm{Ga}}^{3+}$

3.  ${\ln }^{3+}$

4.  ${\mathrm{Al}}^{3+}$

$\mathrm{B}(\mathrm{OH}{)}_3+\mathrm{NaOH}\rightleftharpoons {\mathrm{NaBO}}_2+\mathrm{Na}\left[\mathrm{B}\right(\mathrm{OH}{)}_4]+{\mathrm{H}}_2\mathrm{O}$

How can this reaction is made to proceed in forward direction?

1.  Addition of cis-1, 2 diol

2.  Addition of borax

3.  Addition of trans-1, 2 diol

4.  Addition of ${\mathrm{Na}}_2{\mathrm{HPO}}_4$

Which of the following compound(s) can react with ${\mathrm{BF}}_3$?

1.  Ethers

2.  ${\mathrm{H}}_2\mathrm{O}$

3.  ${\mathrm{NH}}_3$

4.  All of the above